The objectives of this research are directed at characterizing leukemic cell lines representing T-cell, B-cell and null-cell ALL, as well as blastic cells in CML. Search for leukemia specific or associated antigens will be made using these homogeneous cell lines as a model. Comparison between the leukemic cell lines and fresh leukemic cells with respect to their phenotypic expression will be made. Expected results of the above study will be assessed for clinical significance in relation to the diagnosis and prognosis for each subtype of leukemias.